<https://doi.org/10.18710/PNOQCP>
<http://schema.org/description>
"About this dataset: This dataset contains ionograms in PNG format, and covers data from August 01-31, 2003.About the Tromsø Ionosonde (1993-present): Since 1980, the ionosonde was situated at 69° 35' N, 19° 13' E at Ramfjordmoen near Tromsø, Norway and operated by the Auroral Observatory of the University of Tromsø and later on, in collaboration with QinetiQ. The Lowell ionosonde replaced the Auroral Observatory unit in 1992; see the related publication for details."
<https://dataverse.no/dataset.xhtml;jsessionid=b44a188959c6abde1925444a15b8?persistentId=doi%3A10.18710%2FPNOQCP&version=&q=&fileTypeGroupFacet=&fileAccess=&fileSortField=date&fileSortOrder=desc>